A photonic crystal responsive to H-2 has been fabricated by replicating polystyrene colloidal crystal template with WO3 sol-gel, followed with subsequent Pt sputter-deposition. Under H-2 stimulation, the reflection peak of the photonic crystal rapidly shifted to short wavelength and its intensity declined accordingly. The reflection peak returned to its original location after exposure to oxygen atmosphere. The Pt-WO3 photonic crystal also exhibited excellent, tunable optical performance with high sensitivity to hydrogen in the range of 100% to 0.1%. (C) 2012 Elsevier B.V. All rights reserved.